1. Histology- the study of tissue
Tissues
Histology- the study of tissue
Groups of cells that are similar in structure and perform a common or related function.

2. 4 primary types:
Epithelial (covering)
Connective (support)
Muscle (movement)
Nervous (control)

3. Epithelial-
Used for covering (ex: organs) or Glands

4. Epithelial Function-
protection, absorption, filtration, excretion, secretion, sensory reception

5. Characteristics of Epithelial:
-Innervated
-Avascular
-High regenerative capacity
-Polar- Apical surface= free
-Basal surface= attached
-Lots of cells / form sheets

6. 2 names for epithelia:
Layers: simple or stratified
Shapes: Squamous
Cuboidal
Columnar

7. Simple Squamous- thin, permeable, for filtration or exchange, found in lungs, kidneys

8. 2 types:
Endothelium- inner covering, slick friction reducing lining vessels
Mesothelium- middle covering lining the ventral body cavity

9. Simple Cuboidal- secretion and absorption, found in glands

10. A gland consists of one or more cells that make and secrete a product

11. Endocrine gland- ductless, absorb and secrete product by diffusion (thyroid, adrenals, pituitary)
Exocrine gland- ducts (salivary, oil, liver, pancreas)

12. Simple Columnar- lines the digestive tract from stomach to rectum

13. Microvilli- lines intestines, absorbs nutrients
Examples:
Microvilli- lines intestines, absorbs nutrients
Goblet Cells- secretes protective lubricating mucus

14. Stratified Squamous
Stratified Squamous- is most widespread. Thick, protective, and is the external part of skin. Covers tongue, lines mouth, throat, esophagus, anal canal, vagina

15. Epidermis- the outer layer of the skin that contains a protective protein called keratin

16. Stratified cuboidal and stratified columnar are rarer types-found in sweat glands, salivary glands

17. Connective Tissue

18. 2 Parts Fibroblast Chondroblast Osteoblast Hemocytoblast
Cells (living)
Matrix (non-living)
Fibroblast
Chondroblast
Osteoblast
Hemocytoblast
1) Ground Substance:
Amorphous material
2) Fibers:
Collagen
Elastin
Reticular

19. Mesenchyme (embryonic origin)
Fibroblast Chondroblast Osteoblast Hematoblast
Fibrocyte Chondrocyte Osteocyte Blood Cells
Connective
Tissue Cartilage Bone Blood
Proper

20. Connective Tissue Proper
Loose Connective
* Areolar
* Adipose
* Reticular
2) Dense Connective
* Regular
* Irregular

21. Areolar (connective tissue proper)
Gel like, wraps and cushions organs-found in blood vessels, muscles

22. Adipose (fat) connective tissue proper
Matrix contains stored neutral fat oil
Shock absorber and insulator

23. Reticular Connective tissue proper
Forms a soft internal skeleton (stroma)
Found in lymphoid organs-spleen, thymus, lymph nodes

24. Dense Regular connective tissue proper
Parallel collagen fibers
Tendons, Ligaments

25. Dense Irregular connective tissue proper
Thicker bundles of collagen fibers
Forms sheets in body areas where tension is exerted in different directions
Fibrous joint capsules, dermis

26. Cartilage
-Tough but flexible -Avascular -Devoid of nerves -80% water -Heals slowly

27. Cartilage-3 Types 1) Hyaline Cartilage 2) Fibrocartilage
3) Elastic Cartilage

28. 1) Hyaline Cartilage embryonic skeleton ends of long bone
costal cartilage (rib)
Nose
trachea, larynx
supports, reinforces
flexible

29. Fibrocartilage
Thick collagen fibers Intervertebral Discs

30. Elastic Cartilage
More elastin fibers
Ear, Epiglottis

31. Bone
1) Compact bone
2) Spongy bone

32. Bone
Hard calcified
matrix
Very well
vascularized
Gives support

33. Mesenchyme (embryonic origin)
Fibroblast Chondroblast Osteoblast Hematoblast
Fibrocyte Chondrocyte Osteocyte Blood Cells
Connective
Tissue Cartilage Bone Blood
Proper

34. Blood
Various Complex Cells

35. Blood Atypical Connective tissue Blood Cells= macrophages, wbc, rbc
Matrix= plasma
Fibers=soluble proteins that are visible in clotting
-Carries gas, nutrients, waste, etc.

36. Nervous Tissue

37. Makes up brain, spinal cord, nerves
Neurons- highly specialized nerve cells-generate and conduct nerve impulses
Supporting cells- no conducting-support, insulate, and protect neurons

38. Muscle Tissue
Highly vascular
Highly cellular
Function= movement

39. Skeletal Muscle Tissue
Voluntary
Attaches to bone, skin
Gross body movements
Long cylindrical, many nuclei
Striated (banded)

40. Skeletal Muscle Picture

41. Cardiac Muscle Tissue Involuntary Walls of the heart Striated Branched
Fit together by intercalated discs

42. Cardiac Muscle Picture

43. Smooth Muscle Tissue
-Involuntary -Function= to propel (squeeze) -Found in walls of hollow organs (uterus), digestive system, urinary system and blood vessels -Spindle shape -Central nucleus -NO STRIATIONS

44. Smooth Muscle Picture

45. Functions of Tissue Protection
Mechanical protection= (barrier) skin, mucosa
Ciliary protection= epithelial (trachea)
Chemical protection= glands

46. Inflammatory response
Occurs when tissues are injured
Non-specific

47. Immune Response Specific Takes longer to come to action
Involves antibodies

48. Tissue Repair
Three steps:
Inflammation
Organization
Regeneration

49. Inflammation Histamine  macrophage, mast cell Capillaries dilate
Leak clotting proteins
Clot  scab

50. Organization Clot  Granulation tissue
New blood vessels  collagen fibers  scar

51. Regeneration
Epithelial cells migrate across granulation tissue and thickens

52. The ability to regenerate:
Good: Epithelial (skin, epidermis, mucosa)
Limited: Smooth muscle, dense regular connective (ligaments, tendons)
Poor: Skeletal muscle, Cartilage